Polycyclic aromatic compounds (PACs) in the Canadian environment: The challenges of ecological risk assessments

Ecological risk assessments (ERAs) of polycyclic aromatic compounds (PACs), as single congeners or in mixtures, present technical challenges that raise concerns about their accuracy and validity for Canadian environments. Of more than 100,000 possible PAC structures, the toxicity of fewer than 1% have been tested as individual compounds, limiting the assessment of complex mixtures. Because of the diversity in modes of PAC action, the additivity of mixtures cannot be assumed, and mixture compositions change rapidly with weathering. In vertebrates, PACs are rapidly oxygenated by cytochrome P450 enzymes, often to metabolites that are more toxic than the parent compound. The ability to predict the ecological fate, distribution and effects of PACs is limited by toxicity data derived from tests of a few responses with a limited array of test species, under optimal laboratory conditions. Although several models are available to predict PAC toxicity and rank species sensitivity, they were developed with data biased by test methods, and the reported toxicities of many PACs exceed their solubility limits. As a result, Canadian Environmental Quality Guidelines for a few individual PACs provide little support for ERAs of complex mixtures in emissions and at contaminated sites. These issues are illustrated by reviews of three case studies of PAC-contaminated sites relevant to Canadian ecosystems. Interactions among ecosystem characteristics, the behaviour, fate and distribution of PACs, and non-chemical stresses on PAC-exposed species prevented clear associations between cause and effect. The uncertainties of ERAs can only be reduced by estimating the toxicity of a wider array of PACs to species typical of Canada's diverse geography and environmental conditions. Improvements are needed to models that predict toxicity, and more field studies of contaminated sites in Canada are needed to understand the ecological effects of PAC mixtures.

Polycyclic aromatic compounds (PACs) in the Canadian environment: Exposure and effects on wildlife

Polycyclic aromatic compounds (PACs) are ubiquitous in the environment. Wildlife (including fish) are chronically exposed to PACs through air, water, sediment, soil, and/or dietary routes. Exposures are highest near industrial or urban sites, such as aluminum smelters and oil sands mines, or near natural sources such as forest fires. This review assesses the exposure and toxicity of PACs to wildlife, with a focus on the Canadian environment. Most published field studies measured PAC concentrations in tissues of invertebrates, fish, and birds, with fewer studies of amphibians and mammals. In general, PAC concentrations measured in Canadian wildlife tissues were under the benzo[a]pyrene (BaP) guideline for human consumption. Health effects of PAC exposure include embryotoxicity, deformities, cardiotoxicity, DNA damage, changes to DNA methylation, oxidative stress, endocrine disruption, and impaired reproduction. Much of the toxicity of PACs can be attributed to their bioavailability, and the extent to which certain PACs are transformed into more toxic metabolites by cytochrome P450 enzymes. As most mechanistic studies are limited to individual polycyclic aromatic hydrocarbons (PAHs), particularly BaP, research on other PACs and PAC-containing complex mixtures is required to understand the environmental significance of PAC exposure and toxicity. Additional work on responses to PACs in amphibians, reptiles, and semi-aquatic mammals, and development of molecular markers for early detection of biological responses to PACs would provide a stronger biological and ecological justification for regulating PAC emissions to protect Canadian wildlife.

Toxicokinetics and bioaccumulation of polycyclic aromatic compounds in wood frog tadpoles (Lithobates sylvaticus) exposed to Athabasca oil sands sediment

We performed accumulation-elimination experiments of polycyclic aromatic compounds (PACs) in wood frog tadpoles (Lithobates sylvaticus) using river sediment from Canada's Athabasca oil sands region. The PACs in wood frog tadpoles were ∼2x higher on average when the animals were in direct contact with PAC-contaminated sediment than when they were separated from the sediment with a screen and exposed only to aqueous PACs. These results suggest that sediment exposure/ingestion contributes as much to PAC accumulation in tadpoles as exposure via aqueous pathways. Alkyl-substituted PAC concentrations in exposed tadpoles exceeded those of the unsubstituted (parent) PACs by about 10 × . Bioaccumulation factors ranged between 0.01 and 4.93, with parent PACs having higher bioaccumulation factors than alkylated PACs. Wood frog tadpoles efficiently eliminated and metabolized most parent and alkyl-substituted PACs, though some compounds (e.g., C4-naphthalenes) had higher bioaccumulation potential and may serve as effective markers of exposure. Here we present a comprehensive analysis of the toxicokinetics and bioaccumulation of PACs (52 analytes) in amphibian larvae, and highlight the importance of sediment exposure when considering the bioaccumulation and potential biological impact of PACs in benthic and epibenthic organisms.

Airborne polycyclic aromatic compounds contribute to the induction of the tumour-suppressing P53 pathway in wild double-crested cormorants

Polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs) and PAH-like compounds are known or probable environmental carcinogens released into the environment as a by-product of incomplete combustion of fossil fuels and other organic materials. Studies have shown that exposure to PACs in the environment can induce both genotoxicity and epigenetic toxicity, but few studies have related PAC exposure to molecular changes in free ranging wildlife. Previous work has suggested that double-crested cormorants (Phalacrocorax auritus; DCCO) exhibited a higher incidence of genetic mutations when their breeding sites were located in heavily industrialized areas (e.g., Hamilton Harbour, Hamilton, ON, Canada) as compared to sites located in more pristine environments, such as in Lake Erie. The aim of this study was to determine if airborne PACs from Hamilton Harbour alter the tumour-suppressing P53 pathway and/or global DNA methylation in DCCOs. Airborne PACs were measured using passive air samplers in the Hamilton Harbour area and low-resolution mass spectrometry analysis detected PACs in livers of DCCOs living in Hamilton Harbour. Further hepatic and lung transcriptional analysis demonstrated that the expression of the genes involved in the DNA repair and cellular apoptosis pathway were up-regulated in both tissues of DCCOs exposed to PACs, while genes involved in p53 regulation were down-regulated. However, global methylation levels did not differ between reference- and PAC-exposed DCCOs. Altogether, data suggest that PACs activate the P53 pathway in free-ranging DCCOs living nearby PAC-contaminated areas.

The dynamic excitation of a granular chain: Contact mechanics finite element analysis and experimental validation

There is currently interest in transmitting acoustic signals along granular chains to produce waveforms of relevance to biomedical ultrasound applications. The study of such a transduction mechanism is greatly aided by the use of validated theoretical models. In view of this, a finite element analysis is presented in this paper. The dynamics of a granular chain of six, 1 mm diameter chrome steel spherical beads, was excited at one end using a sinusoidal displacement signal at 73 kHz, and terminated by a rigid support. Output from this model was compared with the solution provided by the equivalent discrete dynamics model, and good agreement obtained. An experimental configuration involving the same chain, but terminated by an annular support made of a liquid photopolymer resin was also simulated and the velocity of the last sphere obtained through simulation was compared with laser vibrometer measurement, with good agreement. This model was then extended whereby the granular chain was coupled to an acoustic medium with the properties of water, via a thin vitreous carbon cylinder. Finite element predictions of the acoustic pressure indicate that, for a 73 kHz excitation frequency, harmonic rich acoustic pulses with harmonic content close to 1 MHz are predicted.

Ultrasonic propagation in finite-length granular chains

A narrowband ultrasound source has been used to generate solitary wave impulses in finite-length chains of spheres. Once the input signal is of sufficient amplitude, both harmonics and sub-harmonics of the input frequency can be generated as non-linear normal modes of the system, allowing a train of impulses to be established from a sinusoidal input. The characteristics of the response have been studied as a function of the physical properties of the chain, the input waveform and the level of static pre-compression. The results agree with the predictions of a theoretical model, based on a set of discrete dynamic equations for the spheres for finite-length chains. Impulses are only created for very small pre-compression forces of the order of 0.01N, where strongly non-linear behaviour is expected.

Analysis of solitary wave impulses in granular chains using ultrasonic excitation

The propagation of broad bandwidth solitary wave impulses, generated within granular chains by narrow bandwidth ultrasonic excitation, is studied in detail. Theoretical predictions are compared to experimental results. It is demonstrated that the observed effects result from a sum of a solitary wave traveling out from the source with a wave that reflects from the far end of the chain. It is shown that this combination, when used with an excitation in the form of a long-duration tone burst, encourages the generation of multiple impulses with a characteristic periodicity. This study shows that the properties of the chain structure and the excitation can be adjusted so as to generate ultrasonic solitary wave impulses with a high amplitude and known frequency content, which are of interest in applications such as biomedical ultrasound.

The effect of mechanical ventilator settings during ventilator hyperinflation techniques: a bench-top analysis

Ventilator hyperinflations are used by physiotherapists for the purpose of airway clearance in intensive care. There is limited data to guide the selection of mechanical ventilator modes and settings that may achieve desired flow patterns for ventilator hyperinflation. A mechanical ventilator was connected to two lung simulators and a respiratory mechanics monitor. Peak inspiratory (PIFR) and expiratory flow rates (PEFR) were measured during manipulation of ventilator modes (pressure support ventilation [PSV], volume-controlled synchronised intermittent mandatory ventilation [VC-SIMV] and pressure-controlled synchronised intermittent mandatory ventilation [PC-SIMV]) and ventilator settings (including set tidal volume, positive end-expiratory pressure, inspiratory flow rate, inspiratory pause, pressure support, inspiratory time and/or inflation pressure). Additionally, each trial was conducted with high (0.05 l/cmH2O) and low (0.01 l/cmH2O) compliance settings on the lung simulators. Each trial was dichotomised into success or failure under three categories (attainment of PIFR-PEFR less than or equal to 0.9, PEFR/PIFR greater than 17 l/min, PEFR greater than or equal to 40 l/min). A total of 232 trials were conducted (96 VC-SIMV, 96 PC-SIMV, 40 PSV). A greater proportion of VC-SIMV trials were ceased due to high peak inspiratory pressures (35%). However, VC-SIMV trials were more likely to be successful at meeting all three outcome measures (26 VC-SIMV trials, 7 PC-SIMV trials, 0 PSV trials). It was found that manipulation of settings in VC-SIMV mode appears more successful than PSV and PC-SIMV for ventilator hyperinflations.

Isotopic discrimination and kinetic parameters of RubisCO from the marine bloom-forming diatom, Skeletonema costatum

The cosmopolitan, bloom-forming diatom, Skeletonema costatum, is a prominent primary producer in coastal oceans, fixing CO2 with ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) that is phylogenetically distinct from terrestrial plant RubisCO. RubisCOs are subdivided into groups based on sequence similarity of their large subunits (IA-ID, II, and III). ID is present in several major oceanic primary producers, including diatoms such as S. costatum, coccolithophores, and some dinoflagellates, and differs substantially in amino acid sequence from the well-studied IB enzymes present in most cyanobacteria and in green algae and plants. Despite this sequence divergence, and differences in isotopic discrimination apparent in other RubisCO enzymes, stable carbon isotope compositions of diatoms and other marine phytoplankton are generally interpreted assuming enzymatic isotopic discrimination similar to spinach RubisCO (IB). To interpret phytoplankton δ(13) C values, S. costatum RubisCO was characterized via sequence analysis, and measurement of its KCO2 and Vmax , and degree of isotopic discrimination. The sequence of this enzyme placed it among other diatom ID RubisCOs. Michaelis-Menten parameters were similar to other ID enzymes (KCO2 = 48.9 ± 2.8 μm; Vmax = 165.1 ± 6.3 nmol min(-1 ) mg(-1) ). However, isotopic discrimination (ε = [(12) k/(13) k - 1] × 1000) was low (18.5‰; 17.0-19.9, 95% CI) when compared to IA and IB RubisCOs (22-29‰), though not as low as ID from coccolithophore, Emiliania huxleyi (11.1‰). Variability in ε-values among RubisCOs from primary producers is likely reflected in δ(13) C values of oceanic biomass. Currently, δ(13) C variability is ascribed to physical or chemical factors (e.g. illumination, nutrient availability) and physiological responses to these factors (e.g. carbon-concentrating mechanisms). Estimating the importance of these factors from δ(13) C measurements requires an accurate ε-value, and a mass-balance model using the ε-value for S. costatum RubisCO is presented. Clearly, appropriate ε-values must be included in interpreting δ(13) C values of environmental samples.

Herbicide impact on non-target plant reproduction: what are the toxicological and ecological implications?

Declining plant diversity and abundance have been widely reported in agro-ecosystems of North America and Europe. Intensive use of herbicides within cropfields and the associated drift in adjacent habitats are partly responsible for this change. The objectives of this work were to quantify the phenological stages of non-target plants in in-situ field situations during herbicide spray and to compare plant susceptibility at different phenological stages. Results demonstrated that a large number of non-target plants had reached reproductive stages during herbicide spray events in woodlots and hedgerows, both in Canada and Denmark where vegetation varies considerably. In addition, delays in flowering and reduced seed production occurred widely on plants sprayed at the seedling stage or at later reproductive periods, with plants sprayed at reproductive stages often exhibiting more sensitivity than those sprayed as seedlings. Ecological risk assessments need to include reproductive endpoints.

Phytotoxicity testing for herbicide regulation: shortcomings in relation to biodiversity and ecosystem services in agrarian systems

The purpose of this paper is to present current knowledge on methods employed to perform phytotoxicity tests and risk assessments and to highlight shortcomings in relation to biodiversity and ecosystem services. Ecosystem services are benefits provided to humankind by a multitude of organisms present in natural ecosystems. Several studies were conducted between 2001 and 2010 aimed at investigating some of the deficiencies in phytotoxicity testing (new and existing data are presented). Herbicide toxicity responses were similar when comparing a suite of crop versus wild species. However, the validity of the evaluation was limited because of the narrow types of species tested. The number of species tested, currently set between six and ten, appears insufficient. The trait-based approach (i.e. the use of plant attributes to predict species sensitivity to toxicants) can be used to improve species selection. This approach puts more emphasis on the shared biological characteristics that affect plant function within ecological communities rather than on plant phylogeny. Results presented showed that further studies are needed. In test guidelines, protocols require that crop species be sprayed as young vegetative plants, which is assumed to be the most sensitive growth stage to herbicides. In contrast, during herbicide spray, herbicides may reach non-target plants that are at various phenological stages. Several studies demonstrated that plants may be at greater risk when contamination occurs at the reproductive stage. No data on long-term effects, plant recovery or on effects on reproductive stages are requested in current guidelines. Preliminary evidence suggests that this may be an important aspect to consider in risk assessment. In addition, herbicide impacts on plant community diversity as well as biodiversity at other trophic levels have been demonstrated in only a limited number of studies and therefore should warrant more attention in risk assessment.

Production of degenerate polarization entangled photon pairs in the telecom-band from a pump enhanced parametric downconversion process

The design and implementation of a novel source of degenerate polarization entangled photon pairs in the telecom band, based on a cavity enhanced parametric downconversion process, is presented. Two of the four maximally entangled Bell states are produced; the remaining two are obtainable by the addition of a half wave plate into the setup. The coincident photon detection rate in the A/D basis between two detectors at the output of the device revealed the production of highly entangled states, resulting in quantum interference visibilities of 0.971 ± 0.041 (ϕ = 0 state) and 0.932 ± 0.036 (ϕ = π state) respectively. The entangled states were found to break the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality by around 6 standard deviations. From the measured coincidence counting rates and the optical system losses, an entangled photon pair production rate of 8.9 × 10(4) s(-1) mW(-1) pump was estimated.

The Hong-Ou-Mandel interferometer: a new procedure for alignment

Two major requirements in the construction of the Hong-Ou-Mandel interferometer are the alignment and length balancing of two optical paths. A new method is presented for meeting these requirements that requires no custom optics or expensive equipment. Using this method, a two photon interferometer sourced by degenerate noncollinear parametric photon pairs was aligned and the optical paths were balanced to within an average of 11.6 microm, yielding two-photon interference features with visibilities of approximately 0.9. The method is applicable to arbitrary noncollinear emission angles, including nondegenerate downconversion situations where the signal and idler emission angles differ.

Spatiotemporal segregation-pattern drift in particle-laden rimming flow

In a previous publication [O. A. M. Boote and P. J. Thomas, Phys. Fluids 11, 2020 (1999)10.1063/1.870065], we described a new banding pattern developing from particle segregation in particle-laden flow inside a partially fluid-filled, horizontal, rotating cylinder. Here we discuss long-term observations lasting up to several weeks revealing that the system can display an extremely rich spatiotemporal behavior that emerges as the patterns drift very slowly along the axis of rotation. Some of the nondimensional key parameters governing the dynamics are identified.

Micrometric granular ripple patterns in a capillary tube

The oscillatory motion of a fluid carrying micron-sized particles inside a capillary tube is investigated experimentally. It is found that initially uniformly distributed particles can segregate and accumulate to form regularly spaced micron-sized particle clusters. The wavelength of the microclusters is compared to data for macroscale sand-ripple patterns and found to obey the same universal scaling as these. A dimensional analysis is performed that confirms the universality of the experimentally observed scaling. The experimental data for the microripple clusters further suggest the existence of a minimum particle length scale for which patterns can form and below which the Brownian motion associated with the molecules of the matrix fluid inhibits pattern formation.

Is there evidence to support the use of lateral positioning in intensive care? A systematic review

A systematic review of randomised clinical trials was conducted to investigate the efficacy and safety of use of the lateral position in the management of ventilated intensive care patients. One review article and 11 empiric studies, which were mostly of low methodological quality, met the eligibility criteria. Large individual variations in PaO2 response to lateral positioning were demonstrated. Greatest improvement in PaO2 occurred in patients with unilateralpulmonary infiltrates positioned with the bad lung up versus bad lung down (average difference = 33.6 mmHg (range 0-58), effect size 1.13 (95% CI: 0.44, 1.19, P = 0.001)) or supine (average difference=27 mmHg (range 5-42), effect size 0.58 (95% CI: 0.11, 1.06, P = 0.017)). This effect appeared to be most prominent in patients with widespread, unilateral infiltrates. Lung compliance was not affected by lateral positioning. Haemodynamic compromise was evident with lateral positioning of greater than 60 degrees to the right side in patients requiring vasopressors and/or with right ventricular dysfunction; or with lateral positioning in postoperative coronary artery bypass graft patients. No studies were found that had investigated the effect of routine applications of the lateral positioning to improve, prevent or treat pneumonia, decrease mortality or influence other long-term outcomes. The results of this review demonstrate the limited evidence available to support the use of lateral positioning in the intensive care environment. More data reporting the long-term effects of lateral position on long-term outcomes would aid clinical decision making and may improve the application of patient positioning in critical care environments.

Asymmetric Hydroformylation of Vinyl Acetate: Application in the Synthesis of Optically Active Isoxazolines and Imidazoles

(R)- and (S)-2-(Acetyloxy)-propanal were prepared [93.8% ee, 102 b/l for (R), 96.9% ee, 149 b/l for (S)] via asymmetric hydroformylation of vinyl acetate on a 150-180 g scale and were used as the starting materials in the synthesis of chiral isoxazoline and imidazole derivatives which proceeded without racemization of the chiral center.

When Does It Hurt? Pain during Flexible Cystoscopy in Men

INTRODUCTION

In this observational study, pain was measured continuously in men undergoing flexible cystoscopy, in order to help to identify which parts of the procedure were the most painful.

PATIENTS AND METHODS

Men who were to undergo flexible cystoscopy were recruited. Pain was measured continuously throughout flexible cystoscopy by asking the subject to squeeze a pressure-sensing rubber bulb in proportion to the amount of discomfort experienced giving a score of 0-10.

RESULTS

The most painful part of the procedure was as the cystoscope passed through the membranous urethra with a median pain score of 2.82. The initial lidocaine administration gives a median pain score of 0.84. The other parts of the cystoscopy produced median scores of between 0.14 and 0.33. The difference in the pain scores was significant (p = 0.03). There was no statistically significant difference in the pain scores between those who were having their first cystoscopy and those who were having repeat cystoscopy. The subjects' age did not influence the degree of pain experienced.

CONCLUSION

This study gives further understanding of how pain is experienced during flexible cystoscopy. It may help explain why previous studies have not reached a clear consensus on the value of lidocaine during flexible cystoscopy.

Infectious swine hepatitis E virus is present in pig manure storage facilities on United States farms, but evidence of water contamination is lacking

Fresh feces, manure slurry (from earthen lagoons and/or concrete pits), and drinking and surface water samples were collected from 28 pig farms in the Midwestern United States. All samples were tested for hepatitis E virus (HEV) RNA by reverse transcription-PCR. Seven of 28 farms had fecal samples that contained HEV. Of 22 farms where pit samples were accessible, 15 contained HEV, and of 8 farms that had lagoons, 3 contained HEV. The highest virus titers were 10 and 10(3) genome equivalents per 60 ml of manure slurry in lagoon and pit samples, respectively. None of the water samples tested HEV positive. To determine the infectivity of the HEV found in the positive farm 19 lagoon (designated L19) or farm 12 pit (designated P12) samples, pigs were inoculated either intravenously (n = 3) or orally (n = 3) with the L19 or P12 manure slurry. Four pigs inoculated intravenously with prototype swine HEV served as positive controls. All positive-control pigs shed HEV in feces and 3 of 4 developed anti-HEV antibodies. Two pigs in the intravenously inoculated P12 group shed HEV in feces, and one of the pigs seroconverted to anti-HEV antibodies. None of the pigs in the negative-control, L19 oral, L19 intravenous, or P12 oral group shed HEV in feces. The findings indicate that HEV found in pig manure slurry was infectious when inoculated intravenously. Pit manure slurry is a potential source of HEV infection and for contamination of the environment. Contamination of drinking or surface water with HEV was not found on or near the pig farms.

Granular ripples under rotating flow: a new experimental technique for studying ripples in non-rotating, geophysical applications?

A review of our research investigating a new pattern formation process in granular material underlying a rotating fluid is given. The purpose of this summary is to introduce the phenomenon to the geophysical research community and to draw attention to the potential practical benefits of our new experimental method. To this end, the applied and scientific advantages of the technique over traditional studies employing, for instance, water channels, are discussed for the first time. It is shown here that the system rotation in our new technique does not appear to affect the scaling law expressing the dependence of the ripple-pattern wavelength on the governing independent experimental parameters. This suggests that it may become possible to extrapolate appropriate results from rotating to non-rotating systems and, hence, to geophysical environments. Consequently, our new technique may find applications in the context of geophysical research on the formation of sedimentary granular ripple structures.

Routes of transmission of swine hepatitis E virus in pigs

Hepatitis E virus (HEV) is believed to be transmitted by the fecal-oral route in pigs. To date, in experiments, HEV has been transmitted successfully only by the intravenous or intrahepatic route. To assess the route of HEV transmission, 27 pigs were separated into nine groups of three pigs. Positive-control pigs were inoculated intravenously with swine HEV and served as the source of HEV for the other groups. Uninoculated contact pigs were placed in the positive-control group. On three consecutive days, naive pigs were inoculated using samples collected from the positive-control pigs at 9, 10, and 11 days postinoculation. The tonsils and nasal mucosa of each positive-control pig were swabbed and that swab was used to rub the tonsils and nasal and ocular mucosa of naive pigs. The positive-control pigs were also injected with bacterin, and the same needle was used to immediately inject naive pigs. Feces were collected from positive controls and fed by oral gavage to naive pigs. Weekly fecal and serum samples from each pig were tested for anti-HEV antibodies and HEV RNA. All positive-control pigs shed the virus in feces; two pigs were viremic and seroconverted to anti-HEV. All contact control pigs shed the virus in feces; two seroconverted and one became viremic. One of three pigs in the fecal-oral exposure group shed the virus in feces and seroconverted. Pigs exposed to the contaminated needles or the tonsil and nasal secretion swabs remained negative. This is the first report of experimental fecal-oral transmission of HEV in swine.

Prostaglandin E2 and bethanechol in combination for treating detrusor underactivity

OBJECTIVE

To test the hypothesis, in a prospective randomized double-blind study, that the combination of intravesical prostaglandin E2 (PGE2) and oral bethanechol chloride (BC) are additive or synergistic in improving bladder emptying, as they have been used alone for treating impaired detrusor contractility with little clinical benefit.

PATIENTS AND METHODS

Nineteen patients with detrusor underactivity (17 men and two women) were eligible and randomized to one of two treatments. All had postvoid residual urine volumes (PVR) consistently of > 300 mL, most being reliant on clean intermittent self-catheterization (CISC). The experimental treatment group (nine patients) received once-weekly intravesical PGE2 (1.5 mg in 20 mL 0.9% saline) plus BC 50 mg four times daily, for a total of 6 weeks. The second group of 10 patients received a once-weekly instillation of saline together with placebo tablets, again for 6 weeks.

RESULTS

Before treatment the median (interquartile range) PVR was 426 (405-480) mL for those receiving both drugs; this decreased to 325 (290-352) mL after completing the treatment (P < 0.015). In the placebo group the respective values were 576 (539-777) and 538 (350-775) mL (P = 0.09). Four of the patients receiving the active combination reported symptomatic improvement and were able to reduce the frequency of CISC.

CONCLUSION

Although there was evidence of a pharmacological effect, BC and PGE2 had a limited therapeutic effect compared with placebo. Whilst we would not recommend this treatment as routine, it may be considered for the occasional treatment of a patient with detrusor underactivity.

Comparative analyses of multi-species sequences from targeted genomic regions

The systematic comparison of genomic sequences from different organisms represents a central focus of contemporary genome analysis. Comparative analyses of vertebrate sequences can identify coding and conserved non-coding regions, including regulatory elements, and provide insight into the forces that have rendered modern-day genomes. As a complement to whole-genome sequencing efforts, we are sequencing and comparing targeted genomic regions in multiple, evolutionarily diverse vertebrates. Here we report the generation and analysis of over 12 megabases (Mb) of sequence from 12 species, all derived from the genomic region orthologous to a segment of about 1.8 Mb on human chromosome 7 containing ten genes, including the gene mutated in cystic fibrosis. These sequences show conservation reflecting both functional constraints and the neutral mutational events that shaped this genomic region. In particular, we identify substantial numbers of conserved non-coding segments beyond those previously identified experimentally, most of which are not detectable by pair-wise sequence comparisons alone. Analysis of transposable element insertions highlights the variation in genome dynamics among these species and confirms the placement of rodents as a sister group to the primates.

The role of transarterial embolization in the treatment of renal cell carcinoma

OBJECTIVE

To review the role of transarterial renal embolization in our unit, assessing the indications, tolerability and efficacy of this technique for treating renal cell carcinoma (RCC).

PATIENTS AND METHODS

Thirty patients undergoing transarterial embolization between 1991 and 1999 were identified and 25 case notes analysed retrospectively.

RESULTS

Most patients (14 of 25) presented with less advanced (stage I-III) RCC who were unable or unwilling to undergo radical surgery; the remainder (11) presented with advanced (stage IV) disease. The embolizing agent was ethanol, usually combined with stainless steel coils (85% of cases). Procedural pain and fever was controlled successfully. The median hospital stay associated with the procedure was 4 days. At the time of analysis six of 11 stage IV and 11 of 14 stage I-III patients were alive (median follow-up 27 and 39 months, respectively). Symptoms from the primary tumour were well controlled. Overall, 17 of 25 (68%) of patients reported no problems while three (12%) required brief hospital admission for treatment of persistent haematuria. Fourteen patients were subsequently re-staged; the primary tumour in two had increased, in seven remained unchanged and in five it decreased. No patients without metastases developed them and metastases in two patients regressed.

CONCLUSION

Transarterial embolization is associated with minimal morbidity and complications, and subsequent symptom control is good. The effect of palliative embolization on RCC progression is unknown and requires prospective investigation. Presently, there is no role for cytoreductive embolization; it should be included as a treatment option in clinical trials evaluating such options in patients with metastatic RCC.

A prospective controlled quantitative study of ultrastructural changes in the underactive detrusor

PURPOSE

We quantify and compare ultrastructural changes seen at high power on electron microscopic examination of detrusor biopsies from underactive and control bladders.

MATERIALS AND METHODS

The detrusor underactivity group consisted of 14 patients (mean age 64.0 years) with post-micturition residuals greater than 300 ml., impaired contractility and no obstruction on urodynamics. A total of 17 patients who voided normally voiders with residual volume less than 50 ml. served as the control group. Bladder biopsies were obtained endoscopically using cold cup technique and processed using standard methods. All specimens were randomized and studied at high power (x12,000 to x24,000) by an examiner who was blinded to the groups. All complete cells within each random grid field were counted up to a total of 500. The number of disrupted cells per 500 cells was noted.

RESULTS

Disruptive cell profiles were found in all biopsies. Median cell count was 20 cells/500 in 14 controls and 96.5 cells/500 in the underactive detrusor group (p <0.001). The number of disruptive cell profiles did not correlate with age in the control group (r = 0.34, p = 0.18).

CONCLUSIONS

There were distinct morphological changes in the detrusor associated with bladder dysfunction with approximately 4 times more disruptive cells in patients with an underactive bladder. However, there was no correlation between age and number of disruptive cells, suggesting that this is not a process of aging per se. Ultrastructure studies may have a role as an adjunct to urodynamics in the diagnosis of bladder dysfunction.

A prospective evaluation of detrusor ultrastructural changes in bladder outlet obstruction

OBJECTIVES

To characterize the ultrastructure of detrusor smooth muscle from the bladders of symptomatic men with bladder outlet obstruction (BOO) caused by benign prostatic enlargement (BPE) and compare this with a matched control group; to determine how detrusor morphology relates to urodynamic findings and to develop a better understanding of the natural development of bladder dysfunction related to BOO.

PATIENTS AND METHODS

Twelve men (mean age 66 years, range 52-77) with urodynamically confirmed BOO caused by BPE and 12 age-matched asymptomatic normally voiding controls (mean age 67.8 years, undergoing cystoscopy for other conditions) had detrusor biopsies taken endoscopically. The biopsies were processed for electron microscopy using standard methods. The specimens were randomized and examined at medium power (x 4000) by an examiner unaware of the urodynamic findings. Any ultrastructural patterns identified subjectively were noted.

RESULTS

In the BOO group eight of the 12 men had a myohypertrophic pattern, half of which were associated with a degenerative pattern of hypocontractility. Of the remaining four patients, two had the degenerative pattern alone and two were normal. The six men whose biopsies had a degenerative pattern had consistent postvoid residual volumes of > 150 mL; the remainder all had volumes of < 150 mL. There were no ultrastructural abnormalities in the control patients.

CONCLUSIONS

There are interesting qualitative ultrastructural changes in the obstructed detrusor, but they are not consistent enough to provide a reliable diagnostic tool. However, there may be an important relationship between the degenerative pattern and postvoid residual volume in BOO.

Universal scaling for ripple formation in granular media

The wavelength scaling of ripple patterns formed by granular materials underneath flowing fluids is investigated. Experimental results from five systems involving substantially different experimental conditions are compared to each other. The data analysis reveals that all systems display a common, global scaling behavior for the onset of ripple formation on short time scales. This suggests the existence of common physical mechanisms governing ripple formation in these systems.

A qualitative ultrastructural study of the hypocontractile detrusor

PURPOSE

It has been proposed that precise and specific ultrastructural patterns exist in the dysfunctional human detrusor. We evaluated ultrastructural changes in the hypocontractile detrusor and examined the technique of detrusor muscle biopsy and its clinical application.

MATERIALS AND METHODS

After clinical and urodynamic evaluation 19 male and 2 female patients with severe hypocontractility were entered into this prospective study. All patients had a post-void residual urine volume of consistently greater than 300 ml. and were classified as weak or very weak according to the Schäfer nomogram. Multiple biopsies were obtained with the patient under general anesthesia using the cold cup technique. Subsequent specimens were processed for electron microscopy using standard methods. Biopsies were also obtained from 6 controls with normal voiding parameters.

RESULTS

Cold cup detrusor biopsy provided muscle of sufficient quality for detailed electron microscopic analysis in 26 of the 27 specimens obtained. Previously described criteria of the degeneration pattern were present in all cases of severe hypocontractility. These criteria include widespread disruptive muscle cell profiles with sarcoplasmic vacuolation, disruption of cell organelles and ultimately cell lysis. These features were evident in more than half of the randomly studied fields. In addition, 7 patients had an indistinct muscle fascicle cell arrangement with excessive deposits of collagen and elastic fibers between widely separated muscle cells and in the interstitium. It was suggested that these features represent the hyperelastosis pattern in the chronically over distended bladder. These morphological appearances were not present in any controls.

CONCLUSIONS

This early study would appear to support a morphological basis for detrusor hypocontractility and it reinforces the feasibility of electron microscopy as a potential diagnostic tool. The hypocontractile detrusor has distinct ultrastructural appearances that are easily distinguishable from those of the normal age matched detrusor.

Use of a swine bioassay and a RT-PCR assay to assess the risk of transmission of swine hepatitis E virus in pigs

The objective of this study was to assess the risk of transmission of swine hepatitis E virus (swine HEV) to naïve pigs by inoculation with tissues or feces collected from pigs infected experimentally with swine HEV. Seventy-five, 3-week-old pigs were assigned randomly to 24 groups of 3-4 pigs and inoculated with homogenates of tissues (liver, heart, pancreas, or skeletal muscle) or a suspension of feces from swine HEV-infected pigs collected at 3, 7, 14, 20, 27, or 55 days post inoculation (DPI). Each inoculum was prepared as a 10% suspension (w/v) in PBS buffer and tested by a semi-quantitative RT-PCR for swine HEV RNA and by the swine bioassay. The inoculation route was intravenous for liver, heart and pancreas, and via stomach tube for skeletal muscle and fecal suspension. The liver homogenate inocula and feces collected at 3-7 and 14-20 DPI were positive for swine HEV RNA by RT-PCR. The pigs inoculated with liver homogenates collected at 3-7 and 14-20 DPI developed anti-HEV antibodies and swine HEV RNA was detected in their sera. Pigs inoculated with heart, pancreas, skeletal muscle homogenates or fecal suspensions failed to develop anti-HEV antibodies. These findings suggest that there is a potential risk of transmission of swine HEV via liver tissue from infected pigs in the early stages (3-20 DPI) of infection and the in vitro RT-PCR assay correlates well with the swine bioassay.

Mesoscopic assembly of magnetic Pd-Ni nanocrystals into ordered arrays by using alkane thiols

Two-dimensional arrays of core-shell Pd561 Nin (n = 38, 280, 561, 800, 1500, 3000, 4500) nanocrystals have been prepared by using alkanethiols. The arrays of Pd561 Nin nanocrystals are particularly well ordered; those with high Ni coverage show a tendency to form multilayers or crystallites. Two-dimensional arrays also have been obtained of Pd561 Ni3000 nanocrystals further covered by a Pd layer with a Pd561 Ni3000 Pd1500 composition.

The crystal structure of the MJ0796 ATP-binding cassette. Implications for the structural consequences of ATP hydrolysis in the active site of an ABC transporter

The crystal structure of the MJ0796 ATP-binding cassette, a member of the o228/LolD transporter family, has been determined at 2.7-A resolution with MgADP bound at its active site. Comparing this structure with that of the ATP-bound form of the HisP ATP-binding cassette (Hung, L. W., Wang, I. X., Nikaido, K., Liu, P. Q., Ames, G. F., and Kim, S. H. (1998) Nature 396, 703-707) shows a 5-A withdrawal of a phylogenetically invariant glutamine residue from contact with the gamma-phosphate of ATP in the active site. This glutamine is located in a protein segment that links the rigid F(1)-type ATP-binding core of the enzyme to an ABC transporter-specific alpha-helical subdomain that moves substantially away from the active site in the MgADP-bound structure of MJ0796 compared with the ATP-bound structure of HisP. A similar conformational effect is observed in the MgADP-bound structure of MJ1267 (Karpowich, N., et al. (2001) Structure, in press), establishing the withdrawal of the glutamine and the coupled outward rotation of the alpha-helical subdomain as consistent consequences of gamma-phosphate release from the active site of the transporter. Considering this subdomain movement in the context of a leading model for the physiological dimer of cassettes present in ABC transporters indicates that it produces a modest mechanical change that is likely to play a role in facilitating nucleotide exchange out of the ATPase active site. Finally, it is noteworthy that one of the intersubunit packing interactions in the MJ0796 crystal involves antiparallel beta-type hydrogen bonding interactions between the outermost beta-strands in the two core beta-sheets, leading to their fusion into a single extended beta-sheet, a type of structural interaction that has been proposed to play a role in mediating the aggregation of beta-sheet-containing proteins.

Synthesis of beta-lactones by the regioselective, cobalt and Lewis acid catalyzed carbonylation of simple and functionalized epoxides

The PPNCo(CO)(4) and BF(3) x Et(2)O catalyzed carbonylation of simple and functionalized epoxides in DME gives the corresponding beta-lactones regioselectively in good to high yields. The carbonylation occurred selectively at the unsubstituted C-O bond of the epoxide ring, and this reaction tolerates various functional groups such as alkenyl, halide, hydroxy, and alkyl ether.

Image-spectroscopy--I. The advantages of increased spectral information for compositional EFTEM analysis

The acquisition of a series of energy-filtered TEM images over the energy-loss range of interest creates a three-dimensional data set comprising both spatial and spectral information. Such an image-series contains energy-loss information not available with conventional two- or three-window methods, allowing standard techniques for quantitative EELS analysis to be applied to extracted 'image-spectra'. The increase in spectral information enables improved ionisation edge background extrapolation and interactive image-spectrum analysis to be performed. In this paper, the many advantages of the image-spectroscopy approach are outlined by reference to an example of elemental segregation in an AlZnMgCu alloy.

Image-spectroscopy--II. The removal of plural scattering from extended energy-filtered series by Fourier deconvolution

The increased spectral information obtained by acquiring an EFTEM image-series over several hundred eV allows plural scattering to be removed from loss images using standard deconvolution techniques developed for the quantification of EEL spectra. In this work, both Fourier-log and Fourier-ratio deconvolution techniques have been applied successfully to such image-series. Application of the Fourier-log technique over an energy-loss range of several hundred eV has been achieved by implementation of a novel method that extends the effective dynamic range of EFTEM image-series acquisition by over four orders of magnitude. Experimental results show that the removal of plural scattering from EFTEM image-series gives a significant improvement in quantification for thicker specimen regions. Further, the recovery of the single-scattering distribution using the Fourier-log technique over an extended energy-loss range is shown to result in an increase in both the ionisation-edge jump-ratio and the signal-to-noise ratio.

The 2-year symptomatic and urodynamic results of a prospective randomized trial of interstitial radiofrequency therapy vs transurethral resection of the prostate

OBJECTIVE

To assess the 2-year symptomatic and urodynamic results of a prospective randomized trial of interstitial radiofrequency therapy of the prostate (IRFT) vs transurethral resection of the prostate (TURP).

PATIENTS AND METHODS

Patients with lower urinary tract symptoms (LUTS) and urodynamic evidence of bladder outlet obstruction (BOO) were randomized to undergo IRFT or TURP and were followed up using the International Prostate Symptom Score (IPSS) and urodynamic assessment for 2 years.

RESULTS

At 2 years there was a clinically relevant reduction in the IPSS in the IRFT (20 to 9) and TURP groups (22 to 4). There was also a statistically significant reduction in the detrusor pressure at maximum urinary flow in both groups, but the reduction in the IRFT group was probably not sufficient to explain the observed symptomatic improvements solely from a reduction in BOO.

CONCLUSION

IRFT can produce a sustained improvement in LUTS for at least 2 years. However, such improvements are unlikely to be entirely the result of a reduction in BOO. The effects of radiofrequency energy may, at least partly, be independent of any thermal effect and depend instead on neuromodulation of lower urinary tract nerves.

Crystal structures of the MJ1267 ATP binding cassette reveal an induced-fit effect at the ATPase active site of an ABC transporter

BACKGROUND

ATP binding cassette (ABC) transporters are ubiquitously distributed transmembrane solute pumps that play a causative role in numerous diseases. Previous structures have defined the fold of the ABC and established the flexibility of its alpha-helical subdomain. But the nature of the mechanical changes that occur at each step of the chemical ATPase cycle have not been defined.

RESULTS

Crystal structures were determined of the MJ1267 ABC from Methanococcus jannaschii in Mg-ADP-bound and nucleotide-free forms. Comparison of these structures reveals an induced-fit effect at the active site likely to be a consequence of nucleotide binding. In the Mg-ADP-bound structure, the loop following the Walker B moves toward the Walker A (P-loop) coupled to backbone conformational changes in the intervening "H-loop", which contains an invariant histidine. These changes affect the region believed to mediate intercassette interaction in the ABC transporter complex. Comparison of the Mg-ADP-bound structure of MJ1267 to the ATP-bound structure of HisP suggests that an outward rotation of the alpha-helical subdomain is coupled to the loss of a molecular contact between the gamma-phosphate of ATP and an invariant glutamine in a segment connecting this subdomain to the core of the cassette.

CONCLUSIONS

The induced-fit effect and rotation of the alpha-helical subdomain may play a role in controlling the nucleotide-dependent change in cassette-cassette interaction affinity believed to represent the power-stroke of ABC transporters. Outward rotation of the alpha-helical subdomain also likely facilitates Mg-ADP release after hydrolysis. The MJ1267 structures therefore define features of the nucleotide-dependent conformational changes that drive transmembrane transport in ABC transporters.

Contraceptive use and attitudes toward family planning in Navy enlisted women and men

Little is known about the contraceptive behavior and beliefs of Navy personnel. Nevertheless, the Navy, in its role as primary medical provider for its personnel, needs to know whether sailors have access to effective birth control and are sufficiently informed about contraception to make wise choices. As part of the Women Aboard Navy Ships Comprehensive Health and Readiness Project conducted at the Naval Health Research Center in San Diego, California, contraceptive use and attitudes toward family planning were assessed through a survey administered to 714 enlisted women and 665 enlisted men on 15 ships. Contraceptive use was not related to gender, age, marital status, pay grade, race, or education. More favorable family planning attitudes were related to contraceptive use. Women and men differed in their attitudes toward family planning, with women's responses more positive than men's. The results highlight the need for research focusing on the effect of attitudes on contraceptive behavior.

Penile cancer: a case for guidelines

INTRODUCTION

Aspects of the management of penile cancer remain controversial. In the management of early T1 N0 disease, treatments are divided between amputation and a variety of penis conserving techniques (PCT); local excision, laser techniques, chemotherapy and radiotherapy. We report on a retrospective series of patients with penile cancer.

PATIENTS AND METHODS

Thirty-seven patients were diagnosed between 1987-1996. All patients records were retrieved. Data recorded included TNM stage, histological grade and treatment. The end-points were death, nodal progression and local recurrence.

RESULTS

Median survivor follow-up of 42 months was obtained. Twenty-six patients (70%) presented with T1 disease, 7 (19%) T2 and 4 (11%) T3 or T4. Inguinal nodal disease was seen in 11 (30%). The mean age was 63 years. Overall, 13 penile amputations were performed, 13 underwent radiotherapy, 6 were locally excised in combination with radiotherapy and 3 underwent local excision alone. Two patients were unsuitable for treatment. Of the total (37 patients) 15 have died; 12 from penile cancer. Ten have suffered disease progression and 12 remain alive with no evidence of disease. Twenty-three patients presented with early T1 NO disease. They were treated with radiotherapy (12), local excision (2), combined radiotherapy and excision (2) and partial amputation (4). Outcome was not significantly related to treatment modality. Spread to the inguinal nodes or local recurrence has occurred in 10, of whom 2 have died. Only 13 (57%) appear disease-free.

CONCLUSIONS

The characteristics of the patients and the disease in this series are similar to published series in Europe and North America. There is significant variability in the modalities of treatment used within this series. Local recurrence and disease progression occurs in 43% of T1 N0 lesions. There would seem to be some room for improvement. International data are retrospective and inconclusive with regard to best practice. There is an urgent requirement for randomised controlled trials to improve the outcome of these patients.

Geometric visual hallucinations, Euclidean symmetry and the functional architecture of striate cortex

This paper is concerned with a striking visual experience: that of seeing geometric visual hallucinations. Hallucinatory images were classified by Klüver into four groups called form constants comprising (i) gratings, lattices, fretworks, filigrees, honeycombs and chequer-boards, (ii) cobwebs, (iii) tunnels, funnels, alleys, cones and vessels, and (iv) spirals. This paper describes a mathematical investigation of their origin based on the assumption that the patterns of connection between retina and striate cortex (henceforth referred to as V1)-the retinocortical map-and of neuronal circuits in V1, both local and lateral, determine their geometry. In the first part of the paper we show that form constants, when viewed in V1 coordinates, essentially correspond to combinations of plane waves, the wavelengths of which are integral multiples of the width of a human Hubel-Wiesel hypercolumn, ca. 1.33-2 mm. We next introduce a mathematical description of the large-scale dynamics of V1 in terms of the continuum limit of a lattice of interconnected hypercolumns, each of which itself comprises a number of interconnected iso-orientation columns. We then show that the patterns of interconnection in V1 exhibit a very interesting symmetry, i.e. they are invariant under the action of the planar Euclidean group E(2)-the group of rigid motions in the plane-rotations, reflections and translations. What is novel is that the lateral connectivity of V1 is such that a new group action is needed to represent its properties: by virtue of its anisotropy it is invariant with respect to certain shifts and twists of the plane. It is this shift-twist invariance that generates new representations of E(2). Assuming that the strength of lateral connections is weak compared with that of local connections, we next calculate the eigenvalues and eigenfunctions of the cortical dynamics, using Rayleigh-Schrödinger perturbation theory. The result is that in the absence of lateral connections, the eigenfunctions are degenerate, comprising both even and odd combinations of sinusoids in straight phi, the cortical label for orientation preference, and plane waves in r, the cortical position coordinate. 'Switching-on' the lateral interactions breaks the degeneracy and either even or else odd eigenfunctions are selected. These results can be shown to follow directly from the Euclidean symmetry we have imposed. In the second part of the paper we study the nature of various even and odd combinations of eigenfunctions or planforms, the symmetries of which are such that they remain invariant under the particular action of E(2) we have imposed. These symmetries correspond to certain subgroups of E(2), the so-called axial subgroups. Axial subgroups are important in that the equivariant branching lemma indicates that when a symmetrical dynamical system becomes unstable, new solutions emerge which have symmetries corresponding to the axial subgroups of the underlying symmetry group. This is precisely the case studied in this paper. Thus we study the various planforms that emerge when our model V1 dynamics become unstable under the presumed action of hallucinogens or flickering lights. We show that the planforms correspond to the axial subgroups of E(2), under the shift-twist action. We then compute what such planforms would look like in the visual field, given an extension of the retinocortical map to include its action on local edges and contours. What is most interesting is that, given our interpretation of the correspondence between V1 planforms and perceived patterns, the set of planforms generates representatives of all the form constants. It is also noteworthy that the planforms derived from our continuum model naturally divide V1 into what are called linear regions, in which the pattern has a near constant orientation, reminiscent of the iso-orientation patches constructed via optical imaging. The boundaries of such regions form fractures whose points of intersection correspond to the well-known 'pinwheels'. To complete the study we then investigate the stability of the planforms, using methods of nonlinear stability analysis, including Liapunov-Schmidt reduction and Poincaré-Lindstedt perturbation theory. We find a close correspondence between stable planforms and form constants. The results are sensitive to the detailed specification of the lateral connectivity and suggest an interesting possibility, that the cortical mechanisms by which geometric visual hallucinations are generated, if sited mainly in V1, are closely related to those involved in the processing of edges and contours.

Aberrant CFTR-dependent HCO3- transport in mutations associated with cystic fibrosis

Cystic fibrosis (CF) is a disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). Initially, Cl- conductance in the sweat duct was discovered to be impaired in CF, a finding that has been extended to all CFTR-expressing cells. Subsequent cloning of the gene showed that CFTR functions as a cyclic-AMP-regulated Cl- channel; and some CF-causing mutations inhibit CFTR Cl- channel activity. The identification of additional CF-causing mutants with normal Cl- channel activity indicates, however, that other CFTR-dependent processes contribute to the disease. Indeed, CFTR regulates other transporters, including Cl(-)-coupled HCO3- transport. Alkaline fluids are secreted by normal tissues, whereas acidic fluids are secreted by mutant CFTR-expressing tissues, indicating the importance of this activity. HCO3- and pH affect mucin viscosity and bacterial binding. We have examined Cl(-)-coupled HCO3- transport by CFTR mutants that retain substantial or normal Cl- channel activity. Here we show that mutants reported to be associated with CF with pancreatic insufficiency do not support HCO3- transport, and those associated with pancreatic sufficiency show reduced HCO3- transport. Our findings demonstrate the importance of HCO3- transport in the function of secretory epithelia and in CF.

Protein solubility and folding monitored in vivo by structural complementation of a genetic marker protein

Protein misfolding is the basis of a number of human diseases and presents an obstacle to the production of soluble recombinant proteins. We present a general method to assess the solubility and folding of proteins in vivo. The basis of this assay is structural complementation between the alpha- and omega- fragments of beta-galactosidase (beta-gal). Fusions of the alpha-fragment to the C terminus of target proteins with widely varying in vivo folding yield and/or solubility levels, including the Alzheimer's amyloid beta (A beta) peptide and a non-amyloidogenic mutant thereof, reveal an unambiguous correlation between beta-gal activity and the solubility/folding of the target. Thus, structural complementation provides a means of monitoring protein solubility/misfolding in vivo, and should find utility in the screening for compounds that influence the pathological consequences of these processes.

Interferon gamma regulates accumulation of the proteasome activator PA28 and immunoproteasomes at nuclear PML bodies

PA28 is an interferon (gamma) (IFN(gamma)) inducible proteasome activator required for presentation of certain major histocompatibility (MHC) class I antigens. Under basal conditions in HeLa and Hep2 cells, a portion of nuclear PA28 is concentrated at promyelocytic leukemia oncoprotein (PML)-containing bodies also commonly known as PODs or ND10. IFN(gamma) treatment greatly increased the number and size of the PA28- and PML-containing bodies, and the effect was further enhanced in serum-deprived cells. PML bodies are disrupted in response to certain viral infections and in diseases such as acute promyelocytic leukemia (APL). Like PML, PA28 was delocalized from PML bodies by expression of the cytomegalovirus protein, IE1, and in NB4 cells, an APL model line. Moreover, retinoic acid treatment, which causes remission of APL in patients and reformation of PML-containing bodies in NB4 cells, relocalized PA28 to this site. In contrast, the proteasome, the functional target of PA28, was not detected at PML bodies under basal conditions in HeLa and Hep2 cells, but IFN(gamma) promoted accumulation of ‘immunoproteasomes’ at this site. These results establish PA28 as a novel component of nuclear PML bodies, and suggest that PA28 may assemble or activate immunoproteasomes at this site as part of its role in proteasome-dependent MHC class I antigen presentation.

Is transurethral resection of the prostate safe and effective in the over 80-year-old?

OBJECTIVE

To assess the safety and effectiveness of transurethral resection of the prostate (TURP) in patients over 80 years old.

PATIENTS AND METHODS

The records of all patients over 80 years old undergoing TURP at one institution over a 3.5-year period were studied retrospectively.

RESULTS

31% of patients underwent TURP for symptoms and 68% for urinary retention. The early complication rate was 41%. The late complication rate was 22%. There were no deaths within 30 days of surgery. Of all patients, 80% were satisfied with the outcome of their operation. Of all patients with retention, 80% were able to void with small residual volumes by 6 weeks after operation.

CONCLUSIONS

Although TURP in the over 80-year-old male is associated with significant morbidity, it is an effective treatment for urinary symptoms or retention. The majority of patients are able to void afterwards and are satisfied with the outcome of their surgery.